The invention relates to a multi-layer heat-sealable packaging material especially for food packages. In addition, objects of the invention are a food package formed of the said packaging material, a method of packaging, and the use of the material for packages. The packaging material (1) comprises a middle layer (3) of fibre material, such as cardboard; at least one polymeric protective layer (4, 5) protecting the product from going bad; and polymeric heat sealing layers (2, 7) preferably on both sides of the packaging material. According to the invention, the heat sealing layer (7) forming the inner surface of the closed package, is blended with light-absorbing pigment, such as carbon black, for protecting the product from visible light. By further blending white pigment, such as titanium dioxide, into the heat sealing layer (7), a grey tint resembling an aluminium foil has been achieved for the layer. The heat sealing polymer may be low-density polyethylene (PE-LD), and an oxygen and aroma proof sealing layer (4) of, for example, ethylene vinyl alcohol copolymer (EVOH) or polyamide (PA) may be provided between it and the cardboard (3).